Question

In the root nodules of legumes, leghaemoglobin is important because it

• A. Transports oxygen to the root nodule.
• B. Acts as an oxygen scavenger.
• C. Provides energy to the nitrogen fixing bacterium.
• D. Acts as a catalyst in transamination.

Answer 1

The correct option is B Acts as an oxygen scavenger.

The root nodule bacterium is microaerobic in the sense that it requires oxygen but the high concentration of oxygen is detrimental to nitrogen-fixing enzyme system. Here leghaemoglobin proves beneficial, it absorbs or binds oxygen so that there is no free oxygen left in the nodule and then carries micro-amounts of oxygen to the nodule bacteroids. Thus the correct answer is option B.